Glenoid components generally include a body with two, opposing faces—a first face designed to articulate with either a natural or a prosthetic head of a humerus, and a second face designed to be pressed against the glenoid cavity of a shoulder blade and to be immobilized therein. The first face typically includes a spherical joint surface while the second face is provided with a fin, one or more pegs, or other means for anchoring the component into the bone forming the glenoid cavity.
The two faces of glenoid components are typically designed to be centered on one and the same geometric axis, that axis corresponding to the direction of implantation of the glenoid component into the glenoid cavity. In other words, the spherical joint surface is geometrically centered on a point belonging to the geometric axis and the fin or central anchoring peg, for example, are also centered on the geometric axis.